Fixes three crashes

athena/system/orientation_controller.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ATHENA_SYSTEM_ORIENTATION_CONTROLLER_H_
 #define ATHENA_SYSTEM_ORIENTATION_CONTROLLER_H_
 
 #include "athena/system/device_socket_listener.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
@@ skipping 10 matching lines @@
 namespace athena {
 
 // Monitors accelerometers, detecting orientation changes. When a change is
 // detected rotates the root window to match.
 class OrientationController
     : public DeviceSocketListener,
       public base::RefCountedThreadSafe<OrientationController> {
  public:
   OrientationController();
 
-  void InitWith(scoped_refptr<base::TaskRunner> io_task_runner);
+  void InitWith(scoped_refptr<base::TaskRunner> file_task_runner);
+
+  void Shutdown();
 
  private:
   friend class base::RefCountedThreadSafe<OrientationController>;
 
   virtual ~OrientationController();
 
-  // Watch for the socket path to be created, called on the IO thread.
-  void WatchForSocketPathOnIO();
-  void OnFilePathChangedOnIO(const base::FilePath& path, bool error);
+  void ShutdownOnFILE();
+  // Watch for the socket path to be created, called on the FILE thread.
+  void WatchForSocketPathOnFILE();
+  void OnFilePathChangedOnFILE(const base::FilePath& path, bool error);
 
   // Overridden from device::DeviceSocketListener:
-  virtual void OnDataAvailableOnIO(const void* data) OVERRIDE;
+  virtual void OnDataAvailableOnFILE(const void* data) OVERRIDE;
 
   // Rotates the display to |rotation|, called on the UI thread.
   void RotateOnUI(gfx::Display::Rotation rotation);
 
   // The last configured rotation.
   gfx::Display::Rotation current_rotation_;
 
   // The timestamp of the last applied orientation change.
   int64_t last_orientation_change_time_;
 
+  // True if the OrientaionController has already been shutdown.
+  // This is initialized on UI thread, but must be accessed / modified
+  // only on FILE thread.
+  bool shutdown_;
+
   // A task runner for the UI thread.
   scoped_refptr<base::TaskRunner> ui_task_runner_;
 
+  // A task runner for the FILE thread.
+  scoped_refptr<base::TaskRunner> file_task_runner_;
+
   // File path watcher used to detect when sensors are present.
   scoped_ptr<base::FilePathWatcher> watcher_;
 
   DISALLOW_COPY_AND_ASSIGN(OrientationController);
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_SYSTEM_ORIENTATION_CONTROLLER_H_